The TPS548C26 device offers a power-good output on PG pin, which asserts high when the converter output is within the target. The PG output stays low when the switching is disabled by EN pin or insufficient PVIN level. The PG output is an open-drain output and must be pulled up externally through a pull-up resistor (usually 10 k?). The recommended PG pull-up resistor value is from 1 k? to 100 k?.

The PG function is activated after VCC voltage level reaches the minimum VCC threshold for a valid PG output (maximum 1.2V). When VCC is lower than 1.2V, the PG circuit does not have sufficient power supply and the open-drain output is always high-Z. The power-good function is fully activated after the soft-start ramp is completed and also the 1 ms PG delay expires.